Spiral wound type filter cartridge

ABSTRACT

Disclosed herein is a spiral wound type filter cartridge and more specifically, a spiral wound type filter cartridge in which activated carbon fiber is provided. The inside of spiral wound type filter cartridge is capable of serving as a carbon filter in a water purifier, thus eliminating the necessity of the use of any carbon filter for pre- or post-treatment in the process of purifying raw water, reducing an overall size of the water purifier and considerably reducing costs associated therewith.

TECHNICAL FIELD

The present invention relates to a spiral wound type filter cartridge.More specifically, the present invention relates to a spiral wound typefilter cartridge, inside thereof capable of serving as a carbon filterin a water purifier, thus eliminating the necessity of the use of anycarbon filter for pre- or post-treatment in the process of purifying rawwater, decreasing an overall size of the water purifier and considerablyreducing costs associated therewith.

BACKGROUND ART

With recent economic development, the expansion of industrial scale andthe concentration of big cities and factories have brought about a greatincrease in environmental contamination. As a result, water pollutionhas become a serious problem and drinking water is inevitablely purifiedthrough a water purifier prior to use. A water purifier is necessarilyprovided with a filter to filter raw water and the filter may beselected from a variety of water-purifying filters including non-wovenfabric, activated carbon, activated carbon fiber (ACF), hollow fibermembrane, ion exchange resin and reverse osmosis filters, depending onthe filtering method and steps.

As another conventionally used filter, a spiral wound type filtercartridge is suggested, which is disclosed in detail in Korean PatentNo. 10-0477585, entitled “Method for preparing spiral wound typeseparation membrane module”.

The spiral wound type filter cartridge is generally moduled in a spiralwound shape using a flat-sheet type of ultrafiltration, nanofiltrationor reverse osmosis membranes. In particular, ultrafiltration or reverseosmosis membranes utilize a partial filtration mode and are thus knownto be highly resistant to contamination, compared to filtration modes ofhollow fiber membranes, because a portion of introduced water containingconcentrated contaminants is discharged to a concentrated-waterdischarge line. In addition, flat-sheet membranes used for spiral-woundtype modules are characterized in that they are coated on a non-wovenfabric and are thus more stable to operate at high pressures, ascompared to hollow fiber membranes, and have a maximum efficient areafor a constant volume. Meanwhile, nanofiltration and reverse osmosismembranes generally used as spiral wound type filter cartridges arecapable of removing materials harmful to the human body, for example,waste such as iron or rust, microorganisms and heavy metal ions and arethus widely utilized not only in household water-purifier filtercartridges water but also in industrial water-purifier modules.

The spiral wound type filter cartridge comprises: a filter tube providedwith a purified-water outlet on one side thereof and a plurality ofwater inlet holes in a longitudinal direction on the outside thereof andbeing in the form of a pipe; a filtering sheet repeatedly wound on thefilter tube in the form of a roll, while being fixed on the one side ofthe filter tube under the condition that the one surface of a membranesheet is closely adhered to a mesh sheet; and an adhesive sheet adheredto the filtering sheet such that the filtering sheet takes the circularhousing appearance, while being wound on the filter tube, and is joinedto a case provided with raw water inlet holes such that a purified wateroutlet is exposed to the outside.

When a purified-water inlet holes of filter tube is seen from the top ina longitudinal direction, the filtering sheet has a structure whereinboth sides of the filtering sheet and bottom of the filter tube areclosed by adhesion to take an envelope shape, the membrane sheetarranged at both sides has an inner structure wound in a spiral shapewhile including a mesh sheet for membrane providing a water channel,allowing purified water to flow to a filter tube, and the appearancethereof is wound to maintain the spiral wound state.

The spiral wound type filter cartridge is installed in an appliance suchas a water purifier and carbon filters are provided in an inlet throughwhich raw water enters and in an outlet through which purified water isdischarged. Thus, the spiral wound type filter cartridge, together withthe two carbon filters, sequentially filters the raw water.

The reason for providing carbon filters in the spiral wound typecartridge in pre- and post-treatment processes is that the spiral woundtype filter cartridges can filter particulate materials, microorganismsor toxic minerals, but, of these, in particular, polyamide compositemembranes have disadvantageously poor resistance to materials such aschlorine residues, and carbon filters are capable of efficientlyremoving contaminants such as organic chemicals or offensive odors.

Furthermore, the carbon filters are made of particulate activated carboncomposed of materials such as wood, coconut or coal particlesspecifically heat-treated in order to provide several million fineholes, or of activated carbon fibers prepared by carbonizing fibers, andare used to remove various chemical contaminants. In particular, thecarbon filters are effective in removing organic chemicals such asinsecticides, weedicides or industrial waste and radon, chlorine andoffensive odor thereof and are thus necessarily provided in a filteringarea. However, the carbon filters disadvantageously cannot removemicroorganisms or toxic minerals.

Accordingly, when spiral wound type filter cartridges or carbon filtersare applied to water purifiers, the use of additional carbon filters isinevitably required for the process of pre- or post-treating the filtercartridges, thus disadvantageously incurring costs required for securinga sufficient area of the water purifiers and for installing the carbonfilters.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems, and it is an object of the present invention to provide aspiral wound type filter cartridge, inside of which is capable ofserving as a carbon filter in a water purifier, thus eliminating thenecessity of the use of any carbon filter for pre- or post-treatment inthe process of purifying raw water.

In accordance with one aspect of the present invention for achieving theabove objects, there is provided a spiral wound type filter cartridge,including: a filter tube provided with a purified-water outlet on oneside thereof, the filter tube provided with a plurality of water inletholes in a longitudinal direction on the outside thereof, the filtertube being in the form of a pipe; a filtering sheet comprising amembrane sheet composed of a two-fold sheet to provide a filter areatherein and provided with a mesh sheet for membrane, and a mesh sheetprovided with a channel and laminated on one or both surfaces of themembrane sheet, the filtering sheet being repeatedly wound on the filtertube in the form of a roll, while being fixed on the one side of thefilter tube; an activated carbon fiber provided in the channel of thefiltering sheet or inside the filter tube; and an adhesive sheet adheredto the filtering sheet such that the filtering sheet takes the circularhousing appearance, while being wound on the filter tube.

When the activated carbon fiber is provided in the channel of thefiltering sheet, it may be provided on one or both sides of the meshsheet for membrane or the mesh sheet.

The activated carbon fiber may be in the form of a felt, non-wovenfabric or paper and may be integrally adhesive-bonded to one or all ofthe mesh sheet for membrane, the mesh sheet and inside the filter tube.

The activated carbon fiber may be composed of an activated carbon fibersheet and may be provided in one or both surfaces of at least one of themesh sheet for membrane and the mesh sheet.

The activated carbon fiber sheet may be impregnated or woven from fiberyarns.

The inside of spiral wound type filter cartridge of the presentinvention is capable of serving as a carbon filter in a water purifier,thus eliminating the necessity of the use of any carbon filter for pre-or post-treatment in the process of purifying raw water, decreasing anoverall size of the water purifier and considerably reducing costsassociated therewith.

In addition, the activated carbon fiber is introduced in a spiral shapeinto the spiral wound type filter, thus increasing contact efficiency oftreated water, improving the efficiency of the activated carbon fiber,and imparting desired functions to the activated carbon fiber throughtreatment of high-porisity activated carbon fiber with antibacterials orgermicides.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view illustrating a spiral wound type filtercartridge according to the present invention;

FIG. 2 is an exploded perspective view illustrating a principal part ofthe filter cartridge of FIG. 1;

FIG. 3 is an enlarged view illustrating a longitudinal cross-section ofthe filter cartridge of FIG. 1 or 2;

FIG. 4 is a sectional view illustrating a state in which an activatedcarbon filter sheet is applied according to another embodiment of thepresent invention;

FIG. 5 is an exploded perspective view illustrating a membrane sheetaccording to another embodiment of the present invention;

FIG. 6 is an exploded perspective view illustrating a principal part ofa membrane sheet according to another embodiment of the presentinvention;

FIG. 7 is a sectional view illustrating a state wherein the housing bodyof FIG. 6 is applied to a filter case; and

FIG. 8 is a graph showing a chlorine residue removal ratio as a functionof purified water, for the spiral wound type filter cartridge providedwith the activated carbon fiber sheet and the mesh sheet for membrane.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, exemplary embodiments of a spiral wound type filtercartridge according to the present invention will be described withreference to the annexed drawings in more detail. A detailed explanationof the prior arts related to the description of the present invention isomitted for a clear understanding of the principle of the presentinvention.

The present invention is directed to a spiral wound type filtercartridge constituting a filter for purifying water.

The spiral wound type filter cartridge comprises: a filter tube 100including a purified water outlet 120; a filtering sheet 200 composed ofa membrane sheet 220 provided with a mesh sheet 224 for membrane and amesh sheet 240, serves to guide and purify raw water through a channeland is wound in the form of a roll on the filter tube 100; an activatedcarbon fiber 300 provided in the channel formed by the filtering sheet200; and an adhesive sheet 400 to allow the filtering sheet 200 tomaintain a circular appearance, while wound on the filter tube 120.

The filter tube 100 is in the form of a pipe such that thepurified-water outlet 120 is open at one side thereof and comprises aplurality of purified-water inlet holes 140 arranged in a longitudinaldirection on the outside thereof, to allow purified-water to beintroduced through the purified-water inlet holes 140 and thendischarged through the purified-water outlet 120.

The filtering sheet 200 comprises the membrane sheet 220, and the meshsheet 240 closely adhered to one or both sides of the membrane sheet220, and is repeatedly wound in a screw direction, while the one side ofthe membrane sheet 220 and the one side of the mesh sheet 240 are fixedon the one side of the filter tube 100.

That is, the filtering sheet 200 is repeatedly wound in the form of aroll cake, while the one side thereof is fixed on the filter tube 100.

The membrane sheet 220 is composed of a two-fold sheet to provide afilter area 222 therein and the filter area 222 is provided with a meshsheet for membrane 224.

The preferable activated carbon fiber 300 is in the form of a felt,paper or non-woven fabric, or made by weaving woofs and warps together,and the activated carbon fiber 300 is preferably adhered to the meshsheet for membrane 224 or the mesh sheet 240. Also, the activated carbonfiber 300 is preferably added in the form of a sheet on one or bothsides of the mesh sheet for membrane 224 or the mesh sheet 240.

The activated carbon fiber 300 may be provided for one or both of themesh sheet for membrane 224 provided in the membrane sheet 220constituting the filtering sheet 200, and the mesh sheet 240, dependingon water purification conditions. At this time, the shapes of theactivated carbon fiber 300 may be identical or different.

That is, the activated carbon fiber 300 is integrally bonded to the meshsheet for membrane 224 or the mesh sheet 240, or is made of an activatedcarbon fiber sheet 320, thus being provided on one or both sides of themesh sheet for membrane 224 or the mesh sheet 240. Furthermore, both thebonding and sheet-type addition may be applied.

The activated carbon fiber sheet 320 may be selected from those made bybinding fiber yarns in the form of a felt, paper or non-woven fabric ormade by weaving woofs and warps together.

The activated carbon fiber 300 may have a specific surface area of 500to 3,000 ²/g.

In addition, if necessary, various functional substances may beintroduced as additives to impart various functions to the surface orinside of the activated carbon fiber sheet 320. That is, the functionsmay be imparted by coating additives on the surface of the activatedcarbon fiber sheet 320 or impregnating the same therein for homogeneousdispersion.

The present invention is not particularly limited with regard to theadditives. Specifically, the additives may be selected from the groupconsisting of germicides, antibacterials, mineral agents, pH adjustersand combinations thereof so long as they not deteriorate the functionsof the activated carbon fiber sheet 320.

The additives may be selected by those skilled in the art so as to suitthe apparatus or field to which the filter cartridge according to thepresent invention is applied. For example, an antibacterial may becoated on the activated carbon fiber sheet 320 or impregnated therein toimpart sterilizing and antibacterial actions thereto.

Any antibacterial may be used without particular limitation so long asit is well-known in the art. For example, the antibacterial may beselected from the group consisting of nano-silver, vitamin C, kitosanpowders and combinations thereof. In particular, nano-silver is known tohave superior antibacterial activity. Nano-silver exhibits superiorantibacterial activity to various bacteria, viruses and the like. Morespecifically, in the case where nano-silver is introduced into theactivated carbon fiber sheet 320, an area where the activated carbonfiber sheet 320 is present is in contact with purified and filteredwater, thus allowing the nano-silver to impart antibacterial activity tothe final purified and filtered water and maintaining the antibacterialactivity of the water.

In addition to the antibacterial or separately therefrom, a mineralagent or pH adjuster is coated on the activated carbon fiber sheet 320or impregnated therein to provide mineral water, or alkaline or acidwater through the control of pH.

The mineral agent and pH adjuster may be used without particularlimitation so long as they are known in the art. Examples of usefulmineral agents and pH adjusters include elvan, tourmarine, zeolite,germanium, illite and the like. These ceramics are silicate mineralsincluding alkalis such as sodium, potassium, calcium, magnesium and thelike. The alkali reacts with water in contact with the activated carbonfiber sheet to provide alkaline or mineral active water.

For example, one calcium molecule reacts with two water molecules toform calcium hydroxide, as depicted in the following Reaction Scheme. Inthis process, a portion of electrons derived from calcium is used forformation of hydrogen gas and the remaining electrons are present in thewater and induce formation of hydroxyl groups.

As a result, an increase in hydroxyl groups (OH-) formed from thereaction of calcium and water induces an increase in pH, and the waterbecomes alkaline reduced water and, at the same time, mineral activewater in which the calcium ions (Ca²⁺) are dissolved.

Ca+2H₂O→Ca(OH)₂+H₂(=2H+2e⁻)↑→Ca²⁺+2OH⁻+H₂↑

Accordingly, without purchasing an additional alkaline reduced watersupply device, alkaline reduced water or mineral active water can beobtained by introducing mineral agents or pH adjusters into theactivated carbon fiber sheet 320.

When these additives are applied to the activated carbon fiber sheet320, they are used such that they do not clog the pores of the activatedcarbon fiber sheet 320 and do not impair physical properties. Thecontent of the additives is suitably determined while taking intoconsideration the desired effects, and physical and economicalproperties of the activated carbon fiber sheet 320. Preferably, theadditives are used in an amount of not more than 30 parts by weight,with respect to 100 parts by weight of the activated carbon fiber sheet320.

The adhesive sheet 400 is an element in which an adhesive is appliedonto one side thereof, and is adhered to the filtering sheet 200 suchthat the filtering sheet 200 takes the circular housing appearance,while being wound on the filter tube 100.

In addition, the activated carbon fiber 300 is determined depending onthe contact time of introduced water, the density of activated carbonfiber, the amount of the activated carbon fiber and the amount of waterpassing through the activated carbon fiber, and the activated carbonfiber 300 may thus be manufactured in the form of a felt, non-wovenfabric, paper, sheet or woven fabric.

In addition, the spiral wound type filter cartridge may be provided withan activated carbon 500 in the entire inside of the filter tube 100 orin a predetermined area of the purified water outlet 120. The activatedcarbon 500 may be integrally joined to the filter tube by filling afelt, non-woven fabric or paper shape of activated carbon fiber, orparticle- or block-type activated carbon therein. The block activatedcarbon may be prepared from activated carbon fiber or particulateactivated carbon.

The activated carbon fiber may be further introduced into one or all ofthe mesh sheet for membrane 224 and the mesh sheet 240. The activatedcarbon fiber may be integrally formed with the mesh sheet for membrane224 or the mesh sheet 240 in the form of a felt, non-woven or paper orbe provided in the form of a sheet on one or both surfaces thereof. Inthis case, the germicide, antibacterial, mineral agent, pH adjuster anda combination thereof may also be applied to the activated carbon fibersheet.

As mentioned above, the present invention provides a filter cartridgeprovided with a spiral shape of activated carbon fiber, thus allowinginside of the filter cartridge to serve as a carbon filter andeliminating the necessity of using any carbon filter for the pre- orpost treatment process upon purifying water. As a result, the efficiencywith which the activated carbon fiber contacts treatment waterincreases, thus increasing the efficiency of activated carbon,functionality is imparted to the activated carbon fiber, thus preventingbiological contamination and deterioration in physical properties offilter media (such as ultrafiltration, nanofiltration or reverse osmosismembranes) by organic compounds, due to antibacterial and sterilizationactivities of the filter media. Furthermore, polyamide compositemembranes are used as the filter media to prevent deterioration indurability which may be caused by chlorine residues, thus decreasing theoverall size of water purifiers and considerably reducing costsassociated therewith.

In addition, FIGS. 6 and 7 illustrate another embodiment of the presentinvention. As shown in FIGS. 6 and 7, the filter tube 100 and thefiltering sheet 200 constitute a housing body 800 taking a circularhousing appearance through the adhesive sheet 400 and are thus arrangedin a filter case 600.

The filter case 600 comprises a body 610 which is joined to the housingbody 800 such it covers the housing body 800 and is provided with apurified-water outlet hole 612 in the rear thereof, to allow purifiedwater to be discharged, while passing through the housing body 800, anda cover 620 joined to the front of the body 610 and provided with rawwater inlet holes 622.

A filter block 700 is further provided between an area present in theinside front of the filter case 600 and an area present in the front ofthe housing body 800, to allow introduced raw water to be primarilyfiltered through the filter block 700 and then secondarily filteredthrough the housing body 800.

The filter block 700 serves to filter raw water, which may be composedof various materials such as activated carbon fibers. Representatively,the filter block may take a felt, non-woven fabric, paper or cut-shape.The filter block material may be activated carbon fiber, or particulateor block activated carbon, and the present invention is not limitedthereto.

In addition, an outlet hole 614 is further provided on the rearcircumferential surface of the body 610 constituting the filter case600, to allow the raw water to be filtered through the filter block 700and then to be immediatedly discharged. Accordingly, the final water issuitable for use as living water.

Hereinafter, a process for assembling the spiral wound type filtercartridge and a process for purifying water using the same will bedescribed in detail.

Upon assembly, first, the membrane sheet 220 provided with the meshsheet for membrane 224 is folded in half and a mesh sheet 240 islaminated on one or both sides thereof, to constitute a filtering sheet200. Then, one side of the mesh sheet 240 is fixed on the one side ofthe filter tube 100, an adhesive is applied to the edge thereof and thefiltering sheet 200 is wound in the form of a roll. Subsequently, theadhesive sheet 400 is adhered to one end of the filtering sheet 200 toform the housing body 800 taking a circular appearance.

Then, the housing body 800 is inserted through a packing 260 into thefilter case 600 provided with raw water inlet holes 622 and apurified-water outlet hole 612, the purified water outlet 120 of thefilter tube 100 is closely joined to the purified-water outlet hole 612through a means such as an O-ring such that they communicate with eachother, and the filter case 600 is installed in a water purifier, tocomplete assembly.

Then, when a water purifier is operated, after being introduced throughthe raw water inlet holes 622 of the filter case 600, raw water isprimarily filtered through the filter block 700 and then secondarilywound in the form of a roll, and foreign materials are filtered, whilepassing through the channel provided by the mesh sheet for membrane 224and the mesh sheet 240 inside the membrane sheet 220 constituting thefiltering sheet 200. Simultaneously, the raw water is filtered, whilepassing through the activated carbon fiber 300 arranged depending onwater purification conditions, and is purified through the purifiedwater inlet holes 140 and the purified water outlet hole 120 formed onthe filter tube 100 and then discharged through the purified wateroutlet hole 612.

Hereinafter, preferred examples will be provided for a furtherunderstanding of the invention. The following Examples and ComparativeExamples are for illustrative purposes only and are not intended tolimit the scope of the present invention.

EXAMPLE 1

As shown in FIG. 5, a spiral wound type filter cartridge wasmanufactured from sheets made of activated carbon fiber. Morespecifically, the filter cartridge was manufactured by applying anactivated carbon fiber sheet to the mesh sheet for membrane. 5 tons ofwater was introduced into the spiral wound type filter cartridge thusmanufactured and a chlorine-residue removal ratio was measured. Theresults thus obtained are shown in FIG. 8.

FIG. 8 is a graph showing a chlorine-residue removal ratio as a functionof water to be purified, for the spiral wound type filter cartridgeprovided with the activated carbon fiber sheet and the mesh sheet formembrane.

As shown in FIG. 8, the chlorine residue removal performance is goodeven at an initial water purification stage and stays at about 95% orhigher until the 5 tons of water is completely purified. This behaviorcorresponds to the water flow direction and increases water treatmentcontact efficiency of the activated carbon fiber.

Although the preferred embodiments of the spiral wound type filtercartridge according to the present invention have been disclosed forillustrative purposes, those skilled in the art will appreciate thatvarious modifications, additions and substitutions are possible, withoutdeparting from the scope and spirit of the invention as disclosed in theaccompanying claims.

The present invention is applied to a water purifier filter.

What is claimed is:
 1. A spiral wound type filter cartridge comprising:a filter tube provided with a purified-water outlet on one side thereof,the filter tube provided with a plurality of purified-water inlet holesin a longitudinal direction on the outside thereof, the filter tubebeing in the form of a pipe; a filtering sheet comprising a membranesheet composed of a two-fold sheet to provide a filter area therein andprovided with a mesh sheet for membrane, and a mesh sheet provided witha channel and laminated on one or both surfaces of the membrane sheet,the filtering sheet being repeatedly wound on the filter tube in theform of a roll, while being fixed on the one side of the filter tube; anadhesive sheet adhered to the filtering sheet such that the filteringsheet takes the circular housing appearance, while being wound on thefilter tube; and an activated carbon provided inside of the filter tube.2. The spiral wound type filter cartridge according to claim 1, whereinthe activated carbon is integrally joined to the filter tube by fillinga felt, non-woven fabric or paper type of activated carbon fiber, orparticle- or block type of activated carbon therein.
 3. The spiral woundtype filter cartridge according to claim 1, wherein activated carbonfiber is further provided in one or all of the mesh sheet for membraneand the mesh sheet.
 4. The spiral wound type filter cartridge accordingto claim 3, wherein the surface or inside of the activated carbon fibersheet is coated or impregnated with an additive selected from the groupconsisting of germicides, antibacterials, mineral agents, pH adjustersand combinations thereof.
 5. The spiral wound type filter cartridgeaccording to claim 1, wherein the filter tube and the filtering sheetconstitute a housing body taking a circular housing appearance throughthe adhesive sheet and are arranged in a filter case, wherein the filtercase comprises: a body joined to the housing body so as to cover thehousing body, the body being provided with a purified-water outlet holein the rear thereof, to allow purified water to be discharged, whilepassing through the housing body; and a cover joined in the front of thebody and provided with a raw water inlet hole.
 6. The spiral wound typefilter cartridge according to claim 5, wherein the filter cartridgefurther comprises: a filter block provided between an area present inthe inside front of the filter case and an area present in the front ofthe housing body filter case.
 7. The spiral wound type filter cartridgeaccording to claim 6, wherein the filter block comprises a felt,non-woven fabric, paper or cut shape of activated carbon fiber, orparticulate or block activated carbon.
 8. The spiral wound type filtercartridge according to claim 6, wherein one or more outlet holes arefurther provided on the rear circumferential surface of the bodyconstituting the filter case.